The present invention relates to a call admission priority control determination device and a mobile wireless communication system, and more particularly to a call admission priority control determination device and a mobile wireless communication system using femtocell base stations.
For mobile telephone business operators offering mobile telephone service, it was difficult to set up and operate base stations in such locations as inside of high-rise buildings and residences or underground shopping areas. As a consequence, the elimination of insensitive areas made no satisfactory progress. However, prospects for the elimination of insensitive areas have been improved by the application of femtocell base stations which are simple to handle and can be connected to broadband lines among others.
According to “Guidelines regarding the Application and Related Aspects of the Radio Law, the Telecommunications Business Law and Related Laws or Regulations Pertaining to the Utilization of Femtocell Base Stations” (in Japanese), Dec. 2, 2008, URL: http://www.soumu.go.jp/s-news/2008/pdf/081202—7_bs2.pdf issued by the Ministry of Internal Affairs and Communications, a mobile telephone business operator licensed for femtocell base stations may allow femtocell base station administrators to perform administration of the femtocell base stations by simple handling for transferring, and restoring by utilizing the system of exceptions to the administration of radio stations. The femtocell base station administrators in this context are residents of housing, managers of commercial stores and the like.
JP-A No. 2008-278263 discloses a method of determining a priority cell in communication according to the state of use of wireless resources in each cell, the accommodated traffic volume, the total number of users of cells in the area and the number or ratio of users transmitting on a real time basis. JP-A No. 2008-278263 describes priority between a home cell and a macro-cell; for instance, if the home cell is paid for in a fixed-sum plan which is less costly, the home cell is given priority. According to JP-A No. 2008-278263, each home cell is supposed to be accessible only by a specific user. In this case, this method does not contribute to the easing of macro-cell congestion for any other terminal than that of the specific user. Further, according to JP-A No. 2008-278263, if there is no prescription regarding the priority among plural specific users, the user of a specific terminal such as a home base station operator may therefore suffer deterioration in communication quality due to influences from other users.
Further, IEEE 802.11e prescribes Traffic SPECification (TSPEC) as means of controlling wireless LAN admission. According to this specification, a wireless terminal inquires of the wireless LAN base station at the time of initiating a call whether or not the radio band can be used. The wireless LAN base station judges on the basis of communication already admitted whether or not the new call initiation can be admitted, and communicates the judgment to the wireless terminal. In making this judgment, no priority among users is prescribed, and even the wireless LAN base station may suffer deterioration in communication quality due to influences from other users.
Regarding call admission with a priority level set for a specific user or users, JP-A No. H10-013416 discloses a method by which there is an admission algorithm for each quality class and admission is determined on the basis of comparison of the relative levels between the presumable loss rate and a prescribed value. JP-A No. H07-131462 discloses a method by which call admission is determined by using actual traffic in addition to predeclared traffic parameters.
The setup of femtocell base stations aims, among others, to eliminate insensitive areas of macro-cells in such locations as gaps between buildings, high-rise buildings and underground shopping areas. When insensitive areas of mobile phones are to be eliminated by utilizing a femtocell base station which does not enclose radio waves in a single premises or building, if the femtocell base station is installed within a residence, persons other than the dwellers of that residence can use the femtocell base station. Further, femtocells are also utilized for eliminating the congestion of macro-cells.
In the case described above, when a specified terminal user such as a femtocell base station administrator is engaged in communication within the cell of the base station under its administration, other users may also perform communication within that cell. When more than one terminal is present in the same cell and these terminals communicate with one base station, the wireless resources of that base station are shared among the plural terminals. As a result, the communication rate becomes lower than when communication is performed by only one terminal. Thus, there is a problem that the use of the femtocell base station by other users deteriorates the quality of communication by specified terminal users such as the femtocell base station administrator.